So, generally the Irish programs don't require it. Y'know, being in Ireland and all. But I applied for a grant in the Irish language, so I have to have had 2 years of study, and have to take a placement test before hand. As has already been said, immersion is a great way to go. As soon as you are able, start speaking with natives, even if you make mistakes! Make sure to write, too, and listen to radio, watch movies, etc. in your target language.
Your Fulbright proposal is related to language acquisition? That's awesome. Linguistics is an interest of mine, but something my school didn't offer, sadly. However, my proposal was related to sociolinguistics (don't know if we're allowed to talk about our proposals or not..)